The Pew Research Center's Internet & American Life Project found that 69 percent of adult Internet users, or 52 percent of all US adults, have used the Web to watch or download video.
More US adults are also putting their own content online.
Fourteen percent of adult Internet users said they have uploaded a video online, an increase from eight percent in 2007, with 52 percent saying they shared their video on MySpace or Facebook and 49 percent on YouTube.
Comedy, news popularity up
Fifty percent of adult Internet users said they have viewed comedy videos on the Internet, up from 31 percent in 2007, and 43 percent said they have viewed news videos, up from 37 percent.
Thirty-eight percent said they have viewed educational videos on the Web, up from 22 percent in 2007, and 32 percent said they have watched movies or television shows, twice as many as three years ago.
Political videos were also increasingly popular. Thirty percent said they have watched political videos online, up from 15 percent three years ago.
Most won't pay to view
The number of Web users ready to pay for video content online remains small.
Only one in 10 video watchers, or seven percent of all Internet users, said they have paid to watch or download a video, up from four percent in 2007.
"We are seeing a surge in online video watching," said Kristen Purcell, a Pew associate director for research.
She said the increase was being "driven by a combination of broadband access, the increasing use of social networking sites and the popularity of video-sharing sites."
"Untold numbers of websites now showcase online video as part of their content," she added.
Gen Y biggest online audience
Eighteen- to 29-year-olds were the leading video watchers, according to the poll.
The survey of 1,005 adults was conducted June 18-21 last year and has a margin of error of plus or minus 4.5 percentage points.
It was released a day after Internet tracking firm comScore reported that more than 30.3 billion videos were watched online in the United States in April by nearly 178 million Americans.
